Pertrifluoroacetic acid, oxidation with

Victorian brown coal occurs in five major lithotypes distinguishable by color index and petrography. Advantage has been taken of a rare 100 m continuous core to compare and contrast chemical variations occurring as a function of lithotype classification. For many parameters there is a much greater contrast between the different lithotypes than there is across the depth profile of (nearly) identical lithotypes. Molecular parameters, such as the distributions of hydrocarbons, fatty acids, triterpenoids and pertrifluoroacetic acid oxidation products, together with gross structural parameters derived from IR and C-NMR spectroscopic data, Rock-Eval and elemental analyses and the yields of specific extractable fractions are compared. 

Oxidation with Stoichiometric Oxidants. Certain peracids reacting with alkanes yield alcohols. Peracetic acid,68 69 perbenzoic acid,70 m-CPBA,71,72 and nitroper-benzoic acids may be used. Alcohols or an equilibrium mixture of the alcohol and the trifluoroacetate77 are formed on the action of pertrifluoroacetic acid. A high degree of regioselectivity (better than 97%), specifically, preferential attack at the tertiary C—H bonds, is usually observed ... 

Oxidation of DCC with pertrifluoroacetic acid affords N-trifluoromethyl-N,N -... 

The lithotype profile was investigated in greater detail with the product composition of the different brown coals being reported in Tables 1 and 2. A distinct decrease in the total concentration of detectable oxidation products occurs with darker lithotypes (Table 1). This result is consistent with increasing aromaticity (Figure 2) and the preferential attack on aromatic structures by the pertrifluoroacetic acid reagent. The total destruction of the tertiary structure within the brown coal lithotypes is evidenced by their low yield of insoluble products (Residue) which is primarily composed of mineral matter. 

Pertrifluoroacetic acid-Boron trifluoride (1, 826 2, 316). Hart1 has reviewed oxidation with this system. 

Oxidation of aromatic compounds. Chambers et aO explored oxidation of aromatic hydrocarbons with anhydrous pertrifluoroacetic acid in methylene chloride and, except in the case of benzene and toluene, obtained mixtures shown to contain small amounts of phenols and quinones, as exemplified by the case of m-xylene ... 

Weinreb and co-workers have found some interesting directing effects of the sulfur-oxygen bond in some oxidations of dihydrothiazine oxides. Adduct 64 on oxidation with pertrifluoroacetic acid stereoselectively afforded jS-epoxysultam 67 [Eq. (31)]. 

Pertrifluoroacetic acid, produced in situ from HP and trifluoroacetic anhydride, is an efficient reagent for B V oxidation of butanone to yield ethyl acetate. The possible mechanism of the oxidation of aliphatic ketones by pertrifluoroacetic acid is discussed. Several organic reactions, including BV oxidations, have been studied by using reactivity and selectivity indexes proposed in the DFT. The concepts of electrophilicity and nucleophilicity have been applied as reactivity descriptors. The local hardness has been applied as well as a selectivity descriptor. The reactivity and selectivity patterns have been studied for the reactants involved in these organic reactions. They have been ranked in theoretical scales, which are comparable with experimental results obtained from... 

It was shown that furoxans can be transformed to 1,2,3-triazoles. Thus, 4-acetylamino-3-arylazo-l,2,5-oxadiazole 2-oxides undergo two successive (cascade) mononuclear heterocyclic rearrangements in an aqueous basic medium with the formation of 4-acetylamino-2-aryl-5-nitro-2/7-l,2,3-triazoles (Equation 12) <2001MC230>, or 3,3 -disubsti-tuted 4,4 -azo-l,2,5-oxadiazole 2-oxides were found to undergo a rearrangement into 2-(furoxan-4-yl)-4-nitro-2//-1,2,3-triazole 1-oxides on heating in pertrifluoroacetic or peracetic acids (Equation 13) <2003MC272>. 

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